The black plastic covering on the brake shoe guides was added under the CPSC mandated safety requirements. If the shoe holders don't have it, they are not period correct. These calipers don't look NOS to me anyway, IMHO. Also, the seller has no feedback.
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My C&V Bikes:
1972 Bottecchia Professional, 1972 Legnano Olympiade Record,
1982 Colnago Super, 1987 Bottecchia Team C-Record,
1988 Pinarello Montello, 1990 Masi Nuova Strada Super Record,
1995 Bianchi Campione d'Italia, 1995 DeBernardi Thron